Feed-through switch



NOV. 14, i950 E, LOCKWOQD 2,529,845

FEED-THRUGH SWITCH Filed April 2l. 1947 INVENToR. Edwn H Loc/(wood 4 BY v Patented Nov. 14, 1950 `UNITED STATES PATENT OFFICE FEED -THROUGH ySWITCH Edwin'I-I. Lockwood, Fairfield, Conn., assignorto Casco Products Corporation,-Bridgeport, Conn., a corporation of Connecticut Application April-21, 1947, Serial N 0.742,795

l3 Claims.

Von either side .of an on position,rin such a way that the condition of the switch may be readily determinedrby the sense of touch as well as Visually.

A further object ofthe invention is to provide an improved feed-through switch having novel cord strain-relief means which are extremely effective and at the same time economical to produce and, incorporate.

A still further object of the invention is to provide an electric switch which, in addition to the characteristics above outlined, has long life and is'reliable in operation.

These and other objects are accomplished, in the embodiments of the invention illustrated, by the provision of a novelvcontact and connector .assembly constituting ay majorpart of .the switch and yet involving. relatively few and simple components the assembling of which maybe quickly and economically carriedout as byquickriveting operations, and by the provision of novel casing parts .which cooperate .with ,the said assembly to eliminate separate fastening means therebetween, "andwhichto thefullest. possible extent function also as parts of the switchingmechanism itself, vthereby either entirely eliminating orrelse greatly reducing `the number of V,components or parts heretofore thought to be necessary. ,Moreoven .withthis arrangement the Ysaidvcasing parts may be made identical to each other, thus reducing considerably the initial tool cost, and keeping vtool upkeep, atY a minimum.

The contact and connector assembly may be v handled as a unit,` and inserted asa u nit between thecasingparts and thisfact, together with the elimination of separate fasteningfmeans as such, result in lowerpart and labor costs.

Thex contact. assembly preferably Y comprises a flat base. plate, y,of insulating material, on which stationary contact vnfiembers `are secured and ,to which latterjtlead .wiresfrom electric cords are attached, the plate alsqhaving openingsthrough `which a through lead wire from the cordsmay kbe passed back and forth, thereby to anchor the cords without employing separate anchorage devices.

Cooperable with the stationary contacts of the said assembly is a switch operator having pre-assembled to it a bridging contact member.

kThe switch operator is held in its cooperable operative position by portions of the casing parts,

and by an edge portion of the base plate of the contact .assembly unit, thereby eliminating the need for separate guide parts to control the path of movement of the operator, resulting in a vfurther economy in the manufacture of the switch. Moreover, the cooperation between the base plate and casing parts is such that shifting of the parts one on .the other is effectively prevented, and therefore but a single draw bolt is needed to secure together the casing parts.

In one embodiment of the invention the switch operator is movable in either of opposite directionsfrom the on position, to open the switch circuit, and by this arrangement a user may easily determine solely by the sense of touch whether the switch is on or off.

Other features and advantages will hereinafter fmember.

vFgt-Gis a side elevation of the assembled switch and k Y Fig. 7 Yis a View like Figgl but showing a modication ywherein the switch operator is movable from an on position in either of oppositedirections to off positions.

Referring to Figs. 1, 2 and 6 the switch of the present invention comprises a casing I 8 which preferably has a shape convenient for hold-inglin the hand, the casing being formed ofvtwo halves l! andlz'molded of insulating material.

In conjunction with the casing Ida novel unitary assembly i3 is provided, according to the invention, the said assembly comprising a base Aplate I4 which is preferably of insulating matet rial, and comprising a `pairofstationary contact 3 members I and a pair of two-conductor electric cords I6.

Referring to Figs. 1 and 5 each contact member I5 has a flat base portion I1 with an aperture I8, the base portion having an extended end I9 the tip 26 of which is bent at right angles and is of generally cylindrical shape.

As shown in Fig. 4 the insulating base plate I4 is of generally elongate shape having acurved side edge 2| in which a pair of notches 22 is provided to accommodate the bent tips of the contact members I5, the base portions I1 of the members being secured tothe plate I4 by eyelets 23 which pass through the apertures I8 in the contact members and through corresponding apertures 24 in the base plate I4. Due to the shapes of the notches 28 and locations of the apertures 24 in the base plate, the contact members I5 are securely locked in their operative positions shown and prevented from turning about the eyelets 23.

Prior to securing the contact members I5 to the I base plate I4 the bared ends of lead wires 25 from the cords I6 are interposed between the members and the base plate, whereupon the laying-over of the eyelets secures the lead wires under the base portions of the contact members to form electrical connection therewith.

The cords I6 also have lead wires 26 which are joined together so as to constitute in effect a single through lead wire, and in accordance with the present invention a novel and simplified means for joining and anchoring the lead wires 26 are provided. Referring to Figs. 1 and 4 the base plate I4 is provided with a pair of openings or notches 21 in the side edge 28 opposite the edge 2 I', the said notches being of a size to receive and closely confine the lead wires 2S, and the said wires are passed through the notches 21 from one side of the plate to the other, and secured together, as by a metal clamping sleeve 26a. In so arranging the wires 26 they are provided with reverse bends 29 on opposite sides of the plate I4, Fig. 2, and therefore the wires are effectively anchored against longitudinal shifting with re spect to the base plate.

For cooperation with the stationary contact members I5 a manually operable member 36 is provided, having a iinger-engageable portion 30a and an arcuate slide portion 3 I, said member carrying a metal plunger 32 in a recess 33, the plunger being spring-urged outwardly by a spiral compression spring 34, Figs. 1 ramd 2.

In accordance with the invention the switch operator 33, the base plate I4 of the stationary contact assembly, and the lcasing halves II and I2 are so arranged that the latter may be identical to each other and yet when brought together with the said operator and assembly interposed, will provide a slide for the operator and will clamp and position the base plate I4 of the assembly and prevent movement thereof, all without requiring additional parts or extra .assembly operations. Also, the casing halves are shaped to provide a slot through which the nger engageable portion 39a of the switch operator may project. By the above organization the number of parts required by the switch and labor needed in assembly are considerably reduced.

Accordingly, as shown in Fig. 3, each casing half is made in the form of an elongate shallow `shell having an oblong concavo-convex wall 35,

and having side flanges 36 and 31 extending along opposite side edges of the said wall.

At its ends each casing half has a semi-circular notch or recess 38 which i-n conjunction with similar recesses in the other casing half form opening at the ends of the casing III.` to admit the electric cords I6.

In the center of the flange 36 each casing half has an elongate notch-39, the said notches constituting a slot 39a. when the casing halves are secured together, through which slot the switch operator 36 extends.

For the purpose of positioning and securing the base plate I4 of the contact assembly in the casing I0, the halves II and I2 thereof have ribs 4U located to engage edge portions 4I of the base plate, and have lugs 42 provided with cut-outs or recesses 43 for receiving and nesting the corners 44 of the base plate.

The casing halves are secured together by a bolt 45 which passes through centrally located apertured bosses 46 of the halves, the said bosses being sufficiently long to project into an aperture 41 provided in the base plate I4.

Ribs 48 are also provided on the boses 46 to function as shoulders for engaging opposite sides of the base plate I4 whereby the latter is securely clamped'and rigidly held when the bolt 45 is tightened to bring together the casing halves I I and I2.

It will be noted that the nesting of the corners 44 of the base plate I4 in the recesses 43 of the casing'halves, and the engagement of the edges 4I of the plate with the ribs 4I) of the halves effectively prevent shifting of one casing half with respect to the other even though but a single draw bolt is used in securing together the said halves.

For the purpose of guiding the slide portion 3| of the switch operator 30, a curved track 49 is provided in each casing half, the said tracks and the curved edge 2I of the base plate I4, together with curved walls 50 provided in the casing halves adjacent and co-extensive with the tracks 49, accurately guiding the switch operator 36 in an arcuate path of travel.

Referring to Fig. 1 the plunger 32 of the switch operator is shown as bridging the stationary contact members I5, thereby closing the circuits through the switch. When the switch operator 30 is shifted from the position of Fig. 1 toward the right to a position as shown by the dotted lines of Fig. 1, the plunger 32 will be separated from the left contact member I5, and the circuit through the switch will be opened.

By virtue of the plunger 32 having a rounded end as shown, it will cooperate with the cylindrical tip portions 20 of the contact members I5 to produce a desirable detent action by which the operator 30 will be yieldably held in either closed-circuit position or open-circuit position.

As seen in Fig. 1, the inner surfaces of the flanges 31 of the casing halves extend closely adjacent the notches or openings 21 in the base plate I4 and serve to prevent the lead wires 26 from shifting laterally out of said notches.

By the above construction the manufacture of .the `feed-through switch maybe economically carried out, since as will be seen, but few and simple components are required, and since the assembly of the components may be very quickly and easily done. For example, the attaching of the contact members I5 and lead wires 25 to the plate I4 may be readily accomplished by use of an eyelet or rivet setting machine and the connecting together of the wires 26 done with a foot or kick press. The inserting of the wires 26 in the notches 21 may be easily done by hand after the connecting together of the wires, and the wires are thus anchored without the use of separate anchoring clips or the like. l

After the assembly comprising the plate I4, contact members I and cords I6 is completed, it may be placed between the casing halves II and I2 together with the preassembled operator 30, whereupon the bolt 45 may be applied and the casing halves secured together. This assembling operation may be quickly done, and does not require separate fastening or guide means for the parts within the casing I0, thereby resulting in the economies above mentioned.

I have found that the anchorage of the lead wires 26 as described above is extremely eiective in preventing pullout of the cords I6 from the casing I9 even when the cords are under substantial tensile stress. Due to the fact that the wires 26 are joined to the -wires 25 along their entire lengths in the cords I6, any pulls to which the cords may be subjected will be opposed mainly by the anchorage for the lead wires 26, thereby relieving from stress the connections effected to the wires 25 by the eyelets 23 and contact members I5, which stress could act to weaken said connections or cause failure thereof.

A modication of the invention, wherein the manually operable member of the switch may be shifted in either of opposite directions from its on position, to enable the condition of the switch to be ascertained solely by the sense of touch, is shown in Fig. '7. In this figure, parts which are similar to the parts shown in the preceding figures have been given the same characters.

As shown, the notches 22 of the base plate I4 are located centrally in the curved side edge 2| of the plate, that is, half way between the ends of the plate, instead of slightly off center as shown in Fig. 4. Also, the notches 39 in the flanges 36 of the casing halves are made longer, so that the slot 5I in the casing I9, through which the finger engageable portion 30a of the operator 30 extends, is longer than the notch 39a shown in Fig. 1.

When the switch operator 30 is in its circuitclosing position wherein the plunger 32 bridges the stationary contact members I5, as shown in Fig. '7, the finger engageable portion 36a. of the operator is centralized in the slot 5I. From this centralized position it may be shifted either to the right or to the left, whereupon the plunger 32 will separate from one or the other of the contact members I5 so as to open the circuit of the switch.

A user in operating the switch may thus determine solely by the sense of touch whether the switch is on or off. For example, if the user pushes the portion 39a of the operator to either one of the extreme positions wherein it occupies an end of the notch, he will know that the switch is in open circuit position. From this position it is merely necessary to push the operator in the direction in which movement is possible until the plunger 32 rides over the tip portion 20 of the engaged stationary contact I5 and bridges the said contacts. The detent action of the plunger 32 and spring 33 readily enable a user to ascertain when this new position has been reached, and he will then know that the circuit through the switch is closed. In a similar manner if the switch is in closed-circuit position to begin with,

a user may by the sense of touch set the switch by iirst shifting the operator 36 in either one direction or the other to the limit of its movement, which is then open-circuit position, and proceed as above.

This action of the switch whereby its condition may be ascertained by touch is of considerable advantage in connection with heating pads, in cases where it is difficult or inconvenient for a user to observe the condition of the operator 36, either because of darkness or disability.

Variations and modifications may be made within the scope of this invention and portions of the improvements may be used without others.

I claim:

l. In a switch, a plate having contact members thereon and lead wires connected with said Contact members; a casing comprising two parts secured together and located on opposite sides of said plate and having cooperating shoulders supporting and positioning said plate; said casing including an inwardly-facing channel formed on the interior thereof opposite an edge of said plate; a switch operator slidably engaged in said channel, the edge of said plate opposite said channel having a guard-forming configuration such that the switch operator is prevented from leaving the channel by the edge of said plate.

2. A switch as claimed in claim 1 in which said switch operator includes thereon an element biased towards the edge of said plate, whereby the switch operator is urged outwardly into said channel.

3. A switch as claimed in claim 2 in which each contact member is L-shaped, has one leg thereof fastened to a face of saidv plate, and the other leg thereof overlying said edge in the path of said biased element, the latter being of conductive material and serving, in a certain position of the operator, as an electrical connection between a pair of said contact elements.

EDWIN H. LOCKWOOD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 557,037 Toquet Mar. 24, 1896 1,815,634 Peterson July 21, 1931 1,966,091 Gaynor July 10, 1934 2,117,966 Lobl May 1'7, 1938 2,121,569 Peterson June 21, 1938 2,163,626 Peterson June 27, 1939 2,240,394 Eaton Apr. 29, 1941 2,264,955 Schellenger Dec. 2, 1941 2,313,379 Wood Mar. 9, 1943 2,346,311 Johnson Apr. 1l, 1944 2,356,521 Kochner Aug. 22, 1944 2,368,679 Popp Feb. 6, 1945 FOREIGN PATENTS Number Country Date 49,327 Norway Sept. 28, 1931 295,149 Great Britain Aug. 9, 1928 

